After a breakdown, what should you do to rejoin the main carriageway from the hard shoulder?

Gaining speed on the hard shoulder before merging onto the carriageway is crucial because it helps ensure that your vehicle is traveling at a similar speed to the traffic on the main road. This reduces the risk of creating a dangerous situation where you could collide with vehicles that are already moving at higher speeds.

When you accelerate on the hard shoulder, you can find a suitable gap in traffic, which allows you to merge more safely and smoothly. It's important to remember that merging without checking could lead to serious accidents since the vehicles on the carriageway may be traveling at higher speeds, and if you simply wait for the traffic to stop or only attempt to merge when you perceive light traffic, you might end up causing congestion or dangerous situations rather than resolving your own issue.

Thus, gaining speed ensures you are prepared to join the flow of traffic safely, taking into account that other road users may not expect you to join at a significantly lower speed.